why do Sony claim it's a Carl Zeiss lens when the other manufacturers don't?

The debate rages on, the S75 appears to have the same lens as last years S70 which we discovered is the same as used by Epson's PhotoPC 3000Z, Canon's G1 and a couple of other digital cameras.. This begs the question, who is the original manufacturer and why do Sony claim it's a Carl Zeiss lens when the other manufacturers don't?